NCI Dictionary of Cancer Terms

The NCI Dictionary of Cancer Terms features 7,804 terms related
to cancer and medicine.

Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related
word or phrase in the search box.

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A nutrient that the body needs in small amounts to function and stay healthy. Q10 helps mitochondria (small structures in the cell) make energy. It is an antioxidant that helps prevent cell damage caused by free radicals (highly reactive chemicals). Q10 is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, beef, soybeans, peanuts, and spinach. It is being studied in the prevention and treatment of some types of cancer and heart disease and in the relief of side effects caused by some cancer treatments. Also called coenzyme Q10, CoQ10, ubiquinone, and vitamin Q10.

A process that looks at activities or products on a regular basis to make sure they are being done at the required level of excellence. In clinical trials, QA makes sure that all parts of the trial follow the law and the Good Clinical Practice guidelines. Also called quality assurance.

A form of traditional Chinese mind/body exercise and meditation that uses slow and precise body movements with controlled breathing and mental focusing to improve balance, flexibility, muscle strength, and overall health.

A substance from plants that is being studied together with vaccine therapy for its ability to improve the way the immune system responds to disease. It belongs to the family of drugs called saponin adjuvants.

A drug used to treat bone pain caused by bone cancer and other cancers that have spread to the bone. It contains a radioactive substance called samarium SM 153. Quadramet collects in bone and gives off radiation that may kill cancer cells. It is a type of radiopharmaceutical. Also called samarium Sm 153 lexidronam pentasodium.

An operation to
remove the cancer and some normal tissue around it, but not
the breast itself. Some lymph nodes under the arm may be
removed for biopsy. Part of the chest wall lining may also
be removed if the cancer is near it. Also called breast-conserving surgery, breast-sparing surgery, lumpectomy, partial mastectomy, and segmental mastectomy.

A vaccine that works by stimulating an immune response against four different antigens, such as four different viruses or other microorganisms. For example, Gardasil is a quadrivalent vaccine that helps protect the body against infection with four different types of human papillomaviruses (HPV).

A process that looks at activities or products on a regular basis to make sure they are being done at the required level of excellence. In clinical trials, quality assurance makes sure that all parts of the trial follow the law and the Good Clinical Practice guidelines. Also called QA.

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.